Lens having optics radially symmetrical about different intersecting lines

ABSTRACT

A lens is described which, when in use, transmits light rays emanating from a source thereof mounted in a fixed location with respect to the lens. The lens is made of a light transmitting material and comprises a base portion of uniform thickness having integral therewith a plurality of optics. A central optic is constructed about a line perpendicular to the surface of the base. Each of one or more optics which surround the central optic is radially symmetrical with respect to a line which intersects the line perpendicular to the base and which is at an acute angle therewith. The function of the optics is to efficiently transmit the light rays in a general direction which is not perpendicular to the lens base. This permits the lens to be mounted at an angle which is not perpendicular to the desired direction of light transmittal.

JDU'QuJU United State:

[72] Inventor Nels L. Hansen Allen Park. Mlch.

[2| Appl. No. 60.487

[22 Filed Aug. 3. I970 [45] Patented Nov. 23. I971 [73] Assignee FordMotor Company Dearborn, Mich.

154] LENS HAVING OPTICS RADIALLY SYMMETRICAL ABOUT DIFFERENTINTERSECTING LINES 4 Claims, 2 Drawing Figs.

[52] U.S. Cl 350/l93.

240/1061. 350/21l [51 Int. Cl (102!) 3/08 [50] Field of Search 350/211.193; 240/106. l

[56) References Cited UNITED STATES PATENTS 2,831,394 4/1958 Heenan etal 350/21] X Primary Examiner.lohri K. Corbin Attorneys-John R. Faulknerand Robert W. Brown ABSTRACT: A lens is described which, when in use,transmits light rays emanating from a source thereof mounted in a fixedlocation with respect to the lens. The lens is made of a lighttransmitting material and comprises a base portion of uniform thicknesshaving integral therewith a plurality of optics. A central optic isconstructed about a line perpendicular to the surface of the base. Eachof one or more optics which surround the central optic is radiallysymmetrical with respect to a line which intersects the lineperpendicular to the base and which is at an acute angle therewith. Thefunction of the 0ptics is to efficiently transmit the light rays in ageneral direction which is not perpendicular to the lens base. Thispermits the lens to be mounted at an angle which is not perpendicular tothe desired direction oflight transmittal.

(0 tom; talk 7' PATENTEDNBV 23 ml 3.622.231

INVENTOR KW 5M ATTORNEYS LENS HAVING OPTICS RADIALLY SYMMETRICAL ABOUTDIFFERENT INTERSECTING LINES BACKGROUND OF THE INVENTION light rayspassing through the of the forward movement of the automotive vehicle.

Another situation where it is desirable to have light rays above adoorway and flush with a wall; desirable to have the light which istransmitted through the lens face directed downwardly, rather thanperpendicularly from the lens face.

SUMMARY OF THE INVENTION such light in a general direction that is notperpendicular to the lens face.

The lens of the invention is made from a material capable oftransmitting light, preferably glass or plastic, and is comprised of abase portion having a central optic thereon, the central allysymmetrical about The invention will be better understood by referenceto the description which follows and to the drawings.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a partial emanating from asource (not shown) mounted behind the lenses. The lenses also serve asmeans for protecting the light sources.

Ideally, longitudinal centerline of the vehicle to effect lighttransmisa plurality of optics, denominated I through 14. These opticsare substantially circular in shape. and with the exception of centraloptic I. each of them is defined by at least two surfaces.

The desired general direction of light travel is indicated at it in thatit has a center of curvature located thereon, as is indicated by radiusline 50.

In the embodiment illustrated in Flg. 2, optics 2 through 6 are dioptricoptics, each formed by two surfaces 52 and 54 one of which is refractivewhich intersect to form a peak 56. Surfaces 52 are compound curvedsurfaces, and surfaces 54 are simple curved surfaces. Optics 7 through14 are catadioptric optics, each fonned by two surfaces 58 and 60 one ofmore or less than this number, as is desired.

An axis Y-Y is shown intersecting axis XX, which is peraxis Y-Y forms anacute angle X-X. The acute angle formed Axis Y-Y is a reference axis.Optics 2 through 6 are radiaxes which are parallel to reference axis YYand which also intersect axis X-X. These parallel axes are denominatedin FIG. 2 by the line YY spaced a distance E from axis Y-Y. Preferably,the dimension E from axis Y-Y to axis Y'-Y' is made different for eachof the optics 2 through 6. Thus, the axis Y'Y about which optic 2 isradially symmetrical would be spaced a distance E from reference axisY-Y, and the axis Y-Y' about which optic 3 is radially symmetrical wouldbe spaced a distance E different from the distance 5,, from axis YY.Similarly. the axes YY' for optics 4. and 6 would be spaced respectivedistances E E and E from reference axis Y-Y.

Optics 2 through 6 are radially symmetrical with respect to theirrespective parallel axes Y'Y' in the sense that their respective peaksare located at a constant radial distance D measured from. andperpendicular to. their respective YY axes. Moreover, optics 2 through 6are symmetrical about their respective Y'Y' axes in the sense that theyare comprised of simple curved surfaces 54 which completely, orsubstantially, surround central optic l and which have a constantangular relation with respect to their respective parallel Y' Y axes.Optics 2 through 6 have additional radial symmetry with respect to theirrespective axes Y'Y as a result of the geometrical relation of compoundcurved surfaces 52 with respect to the axes. The symmetry of thesecompound curved surfaces 52 for optics 2 through 6 with respect to theirrespective axes YY ters of curvature. labelled 0, through 0 in FIG. 2.Because of the compound curvature of surfaces 52. these centers ofcurvature are not stationary. but rather form'elliptical loci whichsurround the respective Y'Y axes. The loci of these centers of curvatureappear in the sectional view of FIG. 2 as paired points. o -O 0 -0 etc.

To more fully illustrate the radial symmetry of the curved surfaces 52.particular reference is now made to the curved surface 52 for optic 2and to the centers of curvature 0 -0 therefor. The axis about whichoptic 2 is radially symmetrical is shown in FIG. 2 as axis Y' Y'.,. andit is spaced a distance E from reference axis Y-Y. The radial symmetryresults from the fact that the distance L from points 0 to axis Y Y}.measured perpendicularly thereto. is constant.

The elliptical loci of the centers of curvature 0 -0 0,- O etc. may belocated through the specification of the height of the peaks 56 of theoptics above the plane 44. by specification relative to these peaks ofthe distance D and of the angle made between the radius of curvature andthe Y-Y axis. and also by specifying the dimension for the radiusofcurvature.

Optics 7 through 14 are located a considerable distance form centraloptic l and focal point 40. In view of this. they are made catadioptricoptics. rather than dioptric optics.,in order to effect more efficientutilization of the available light. These optics are defined by twosurfaces. as are optics 2 through 6. However. these optics aresymmetrical about axes Z'-Z' which are parallel to a reference axis Z-Z.Axis Z-Z forms an acute angle with respect to axis X- -X. This anglepreferably is approximately equal to two-thirds of the angle betweenaxis XX and the desired general direction of light travel. Therespective Z'-Z' axes about which optics 7 and 14 are symmetrical arespaced a distance G from reference axis 2-2. which distance may bedifferent for each of the respective optics 7 through 14. The simplecurved surfaces 60 of optics 7 through 14 are radially symmetrical withrespect to their respective ZZ' axes in the sense that they form aconstant angle with respect to these respective axes in a manner similarto that described above for surfaces 54 of optics 2 through 6. There isfurther radial symmetry in that the perpendicular distance F from thepeak of optics 7 to 1] to the respective Z'Z' axes therefor is constantfor each of these optics. Additional symmetry occurs with respect to thecomound curved surfaces 58 of optics 7 through 14. These surfaces havecenters of curvature 0 -0 O,.O,.. etc.. which are located on ellipticalloci which are a constant perpendicular distance from the respectiveZ'Z' axis for the optic under consideration.

may best be described in terms of their cen- From the above. it isapparent that each of the optics 1 through 14 possesses radial symmetrywith respect to an axis. Optic 1 is symmetrical about axis X-X. Each ofoptics 2 through 6 are symmetrical about an axis Y'Y which intersectsthe X-X axis. The YY' and spaced therefrom a distance which, for moreefficient light transmission in a desired general direction, may bedifi'erent for each of optics 2 through 6. The reference axis YYintersects and forms an acute angle with axis X-X, axis X-X beingperpendicular to the base. Each of optics 7 through 14 are symmetricalabout an axis Z'Z' which intersects and forms an acute angle with axisX-X different than the acute angle formed by axis Y--Y. The Z'Z' axesare parallel to a reference axis 2-2 and may be spaced therefrom adistance which may be different for each of optics 7 through 14.

The lens of the invention has been described as having optics located onone side of, and integral with, a base. It should be understood thatadditional optics may be placed on the opposite side of the base todiffuse the transmitted light or to cause other optical effects. Forexample, this opposite surface of the lens may include a plurality ofintegral pillow "optics constructed in a manner well understood in theart.

Various methods may be used for the manufacture of lenses constructed inaccordance with the invention. The preferred method of manufacture forquantityproduction is molding, wherein a mold is made which is thenegative of the lens to be produced. The negative of the various opticsmay be machined into the mold surface. In such case, it may be necessaryto move the cutting tool axially along the axis of symmetry for thenegative of the particular optic being machined. This axial movement ofthe cutting tool may be produced by a cam which axially guides thecutting tool.

Based upon the foregoing description of the invention what is claimedand desired to be protected by Letters Patent is:

l. A lens for the controlled transmittal of light rays emanat- I ingfrom a source mounted in a fixed position with respect to said lens.said lens being made from a material capable of transmitting light raysand comprising:

a base;

a central optic integral with said base and having a refractive surfaceconstructed about a first line perpendicular to said base; and

at least one optic integral with said base and substantially surroundingsaid central optic, said optic being defined by at least two surfacesone of which is refractive and each of which is radially symmetricalwith respect to a second line which intersects the fist line and whichforms an acute angle with the first line whereby light rays aretransmitted in a general direction which is not perpendicular to thelens base.

2. A lens for the controlled transmittal of light rays emanating from asource mounted in a fixed position with respect to said lens. said lensbeing made from a material capable of transmitting light rays andcomprising:

a base;

a central optic integral with said base and having a refractive surfaceconstructed about a first line perpendicular to the surface of saidbase;

a second optic integral with said base and substantially surroundingsaid central optic. said second optic being defined by at least twosurfaces one of which is refractive and each of which is radiallysymmetrical with respect to a second line which intersects the firstline and which forms an acute angle with the first line; and

a third optic integral with said base and substantially surrounding saidcentral optic. said third optic being defined by at least two surfacesone of which is refractive and each of which is radially symmetricalwith respect to a third line which intersects the first line and whichis parallel with the second line whereby light rays are transmitted in ageneral direction which is not perpendicular to the lens base.

3. A lens in accordance with claim 2, which further comprises a fourthoptic integral with said base and substantially surrounding said centraloptic. said fourth optic being defined by at least two surfaces one ofwhich is refractive and each of which is radially symmetrical withrespect to a fourth line which intersects the first line and which formsan acute angle with the first line different from the acute angle formedwith the first line by the second line.

4. A lens for the controlled transmittal of light rays emanating from asource mounted in a fixed position with respect to said lens said lensbeing made from a material capable of transmitting light rays andcomprising:

a base;

a central optic integral with said base and having a refractive surfaceconstructed about a first line perpendicular to the surface of saidbase;

a second optic integral with said base and substantially surroundingsaid central optic, said second optic being defined by at least twosurfaces one of which is refractive and each of which is radiallysymmetrical with respect to a second line which intersects the firstline and which forms an acute angle with the first line; and

a third optic integral with said base and substantially surrounding saidcentral optic, said third optic being defined by at least two surfacesone of which is refractive and each of which is radially symmetricalwith respect to a third line which intersects the first line and whichforms an acute angle with the first line difi'erent from the acute anglefonned with the first line by the second line whereby light rays aretransmitted in a general direction which is not perpendicular to thelens base.

l i i i

1. A lens for the controlled transmittal of light rays emanating from asource mounted in a fixed position with respect to said lens, said lensbeing made from a material capable of transmitting light rays andcomprising: a base; a central optic integral with said base and having arefractive surface constructed about a first line perpendicular to saidbase; and at least one optic integral with said base and substantiallysurrounding said central optic, said optic being defined by at least twosurfaces one of which is refractive and each of which is radiallysymmetrical with respect to a second line which intersects the fist lineand which forms an acute angle with the first line whereby light raysare transmitted in a general direction which is not perpendicular to thelens base.
 2. A lens for the controlled transmittal of light raysemanating from a source mounted in a fixed position with respect to saidlens, said lens being made from a material capable of transmitting lightrays and comprising: a base; a central optic integral with said base andhaving a refractive surface constructed about a first line perpendicularto the surface of said base; a second optic integral with said base andsubstantially surrounding said central optic, said second optic beingdefined by at least two surfaces one of which is refractive and each ofwhich is radially symmetrical with respect to a second line whichintersects the first line and which forms an acute angle with the firstline; and a third optic integral with said base and substantiallysurrounding said central optic, said third optic being defined by atleast two surfaces one of which is refractive and each of which isradially symmetrical with respect to a third line which intersects thefirst line and which is parallel with the second line whereby light raysare transmitted in a general direction which is not perpendicular to thelens base.
 3. A lens in accordance with claim 2, which further comprisesa fourth optic integral with said base and substantially surroundingsaid central optic, said fourth optic being defined by at least twosurfaces one of which is refractive and each of which is radiallysymmetrical with respect to a fourth line which intersects the firstline and which forms an acute angle with the first line different fromthe acute angle formed with the first line by the second line.
 4. A lensfor the controlled transmittal of light rays emanating from a sourcemounted in a fixed position with respect to said lens, said lens beingmade from a material capable of transmitting light rays and comprising:a base; a central optic integral with said base and having a refractivesurface constructed about a first line perpendicular to the surface ofsaid base; a second optic integral with said base and substantiallysurrounding said central optic, said second optic being defined by atleast two surfaces one of which is refractive and each of which isradially symmetrical with respect to a second line which intersects thefirst line and which forms an acute angle with the first line; and athird optic integral with said base and substantially surrounding saidcentral optic, said third optic being defined by at least two surfacesone of which is refractive and each of which is radially symmetricalwith respect to a third line which intersects the first line and whichforms an acute angle with the first line different from the acute angleformed with the first line by the second line whereby light rays aretransmitted in a general directiOn which is not perpendicular to thelens base.